This step is basically moving MySQL data directories to the new Volume, and tell MySQL about it. One thing that I noted that some of the installations have different location for log files and data directories than mentioned here. Also, I found that /etc/mysql directory was non existant. You may look for their location in /etc/my.cnf. If you find there is no /etc/my.cnf, you should create it. (I will tell you later how.)